Method of making semiconductor device comprising a titanium nitride film

Abstract

In a method of forming an adhesive layer for a blanket layer filling a contact hole in a semiconductor device, a Ti film, Ti-rich TiN film or a TiSi x (x being 1.1 to 1.8) film is formed, and then a TiN (stoichiometric) film is formed. The Ti film, Ti-rich TiN film or TiSi x is annealed to be converted into TiSi 2 film. The formation of the Ti film, Ti-rich TiN film or a TiSi x is performed by a continuous CVD process.

What is claimed is: 
     
       1. A method of making semiconductor device comprising the steps of: forming a Ti-rich TiN film in a contact hole formed on a silicon substrate;   forming a stoichiometric TiN film in the contact hole on the Ti-rich TiN film;   forming a blanket film in the contact hole on the stoichiometric TiN film; and   conducting a heat treatment to convert the Ti-rich TiN film into a TiSi 2  film before or after the formation of the blanket film;   wherein the formation of the Ti-rich TiN film and the formation of the stoichiometric TiN film are conducted by a continuous CVD process using a gas containing Ti and a gas containing N as source gases, and initially setting the flow ratio between the Ti-containing gas and the N-containing gas to form the Ti-rich TiN film and then altering the flow ratio into a value for forming the stoichiometric TiN film.   
     
     
       2. The method of claim 1, wherein the formation of the Ti-rich TiN film and the formation of the TiN film are conducted by CVD using the same film-forming chamber and continously. 
     
     
       3. The method of claim 1, wherein the Ti-containing gas is TiCl 4  and the N-containing gas is NH 3 , and the flow ratio between them during the formation of the Ti-rich TiN film is at least 20:1, and the flow ratio between them during the formation of the stoichiometric TiN film is between 10:1 and 20:1. 
     
     
       4. The method of claim 3, wherein the formation of the Ti-rich TiN film lasts about one third of the entire period of the formation of the Ti-rich TiN film and the formation of the stoichiometric TiN film. 
     
     
       5. The method of claim 1, wherein said contact hole is formed on said silicon substrate, at an area where an implanted layer is formed. 
     
     
       6. The method of claim 1, wherein said blanket layer is formed of a refractory metal selected from the group consisting of tungsten, molybdenum and chromium.